Jon Jones didn't want to fight Chael Sonnen on a week's notice, but now the Ultimate Fighting Championship light-heavyweight champion will be subjected to perhaps a crueler fate:

Spending weeks on end around the quick-witted, in-your-face title contender.

UFC President Dana White told The Times on Tuesday that Jones and Sonnen have been assigned as opposing coaches in the third installment of "The Ultimate Fighter" on FX, creating some extensive pre-fight hype for their April 27 pay-per-view title match at a site to be determined.

"The Ultimate Fighter" with Jones and Sonnen is set to begin shooting on Oct. 29 in Las Vegas, with a debut in early January as young middleweights participate in a tournament that leads up to an April "TUF" finale at the Vegas Hard Rock Hotel, where the winner will receive a multi-fight UFC contract.

"This should be a good one," White said of matching arguably his organizationís best fighter against its top personality. "Jon has accepted the fight. He knows the fans want to see that fight."

The April fight date for the two was necessary, White said, because Jones was examined by a doctor in Los Angeles two weeks ago and it was discovered that his right arm, twisted badly in a Sept. 22 bout, had been injured and will require physical therapy and a layoff from mixed martial arts.

Jones, in consultation with trainer Greg Jackson, angered UFC leaders in August by resisting the organization's push to insert Sonnen as a replacement fighter for injured title challenger Dan Henderson of Temecula.

White was beside himself, asking why Jones couldn't take the bout despite having a full training camp while Sonnen was willing to challenge less than two months after a middleweight title loss and with extremely limited preparation time.

For the first time in the organization's history, the UFC took the dramatic step of scrapping its entire Sept. 1 card at Mandalay Bay in Las Vegas. White called the incident "an all-time low."

In declining to face Sonnen in August, Jones (17-1) explained that he wasn't fully comfortable risking the belt against the 35-year-old skilled wrestler with a relentless, attacking style that nearly allowed him to upset middleweight champion Anderson Silva in 2010.

Sonnen (28-12-1) and Silva fought again July 7 in Las Vegas, and Sonnen dominated Silva in the first round, getting atop the champion but failing to deliver painful blows.

Silva quickly rallied in the second, retaining the belt he's owned since 2006 by dropping Sonnen with punches and finishing him by technical knockout with blows that included a knee to the chest.

Predictably, Sonnen has chastised Jones to reporters and on his Twitter account for ducking out of the Sept. 1 challenge.

In August, Sonnen tweeted to Jones: "I know you will never fight me. Don't be afraid. But I'll always be the monster in the closet of your mind, little JJ." After Jones' win over Belfort, Sonnen reminded him: "Iím not going anywhere Johnny!!"

Last week, Sonnen revealed the dialogue that was happening between camps by noting: "You donít give. I TAKE. Remembah that, Bonesie-boy."

Sonnen's ability to penetrate his opponent's psyche emerged in the Silva rematch, with the normally peaceful champion vowing to break the challenger's teeth, arms and legs.